Looks very complicated and expensive to manufacture. The pass-through to the cab however is simple and would be a bonus in the Mav given the short bed.
Once a production line has been rolling for a few years, updates like this can be rolled into the process during a line refresh. But my guess is it's not for this generation of Maverick. Why would I say that? Because Ford doesn't really need to improve the Maverick to sell all they can make. And because build complexity decreases quality. And because Ford is having really expensive quality issues right now.
I'm happy they're improving the 2025 as much as they are, but honestly I don't it was necessary. This years refresh was probably already well in progress by the time Ford realized they had a "can't build enough" hit on their hands.
I'd wager the midgate goes out with the new BEV truck they've announced. And also - Ford and GM hate each other. I mean, hate is too gentle a word. They want to rip each others spines out and hold them up to display to the world as a symbol of corporate victory. So if GM offers a mid gate, then dang it, Ford's gonna offer a mid gate.